QS $21-2($Algo$)$ Identifying cost type LO C$1$

Identify whether each of the following is best described as a fixed, variable, or mixed cost with respect to product units.

$\backslash$table$[[1.$ Depreciation expense on equipment $($straight$-$line$).,],[2.$ Salesperson salary plus commission.,$],[3.$ Depreciation expense of warehouse.,$],[4.$ Hourly wages of assembly$-$line worker.,$],[5.$ Administrative assistant wages.,$],[6.$ Rubber used in making tennis balls.,$],[7.$ Electricity used in factory building.,$]]$